The sale has been envisaged in the latest strategy of the bank, which was endorsed both by the state and the largest partner, the Belgian banking group KBC, said Jasovic.

He does not want to manage the country's biggest bang any more without the support from the state as the majority owner.

The outgoing boss said that when the bank and other owners holding a combined 52.1% stake in Mercator had decided to sell their shares to Agrokor, NLB had immediately started feeling the pressure not to sell.

"This culminated in the clear and explicit position of one of the key owners, which opposes the sale to Agrokor, the closest competitor of Mercator," Jasovic said in reference to the Capital Assets Management Agency (AUKN), which manages state shares in companies.

NLB had acquired the stake in Mercator as collateral for unpaid loans, he said. "It has been clear since the seizure of the stake that the bank has to sell these shares, because they do not belong to the credit portfolio."

He sees the opposition to the sale as a vote of no confidence. "I understand that we are not considered legitimate managers by the biggest owners of the bank any more," Jasovic said, adding that support from owners was of key importance for implementation of strategies.

Jasovic announced his resignation at Tuesday's session of the NLB supervisory board, at which the supervisors decided to postpone the decision on the sale. AUKN told the bank on Monday to consider leaving the decision to the bank's owners in case it does not get an approval from the supervisors.

The supervisory board of NKBM, Slovenia's No 2 bank, endorsed yesterday the sale of the bank's 5% stake in Mercator, while the supervisors of beverage company Pivovarna Lasko are to decide on the sale of the company's 23.34% stake on Friday.

Jasovic was appointed NLB chairman on 1 October 2009 and made the bank react to the crisis with a new strategy that included a withdrawal from non-strategic markets and activities, divestment and cost cutting.

Struggling with increased credit risks, the NLB group recorded a EUR 96.3m loss in the third quarter of this year. It ended 2010 with a EUR 202.3m loss.

AUKN meanwhile said in a press release that the bank would probably not be able to eliminate the loss by the end of the year. "Such results are primarily a reflection of management and supervision of the bank."

Regarding Jasovic's resignation, the agency said that it acted "only in the role of a shareholder and has no influence on appointing the management board members".